Monday, March 19, 2018

Molecular cuisine for gut bacteria .

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Gut bacteria have a very big part in our digestive process as well as our health. Researchers still do not know the kind of food our gut bacteria like to live off of or how they seem to metabolize nutrients. The researchers selected 96 strains from 72 bacterial species, representing the most occurring and abundant species in the human gut. Nassos Typas says in the article, "Our resource provides scientists with tools to experimentally investigate the gt microbiome ecology, going beyond correlations and identifying causes and effects." 

While in the middle of characterising their nutritional preferences for molecules and the gut bacteria the researchers also discovered unknown metabolic features of some other bacteria. Kiran Patil, one of the members of the research team says, "We were surprised to find new bacteria with the capability to utilize mucin, the protein that makes up mucus. These bacteria can contribute to inflammation and infection by weakening the protective mucus barrier lining the gut. Another surprise came from bacteria that proved to be inhibited by amino acids and short-chain fatty acids, common ingredients in most growth media. It turns out that rich media with many nutrients can be toxic for these species, whereas we used to think: the more food, the better." All in all, even closely related bacteria to the gut bacteria sometimes had completely different nutritional preferences.  This new discovery of the gut bacteria will surely impact the medical industry in helping create medicines that are more effective in killing viruses and bacteria in our body that can cause colon cancer or other stomach related issues.

The War Against Antibiotic Resistant Bacteria

The War Against Antibiotic-Resistant  Bacteria

Antibiotic medications are used to kill bacteria, which can cause illness and disease. They have made a major contribution to human health. Many diseases that once killed people can now be treated effectively with antibiotics. However, some bacteria have become resistant to commonly used antibiotics. Antibiotic-resistant bacteria are bacteria that cannot be killed by antibiotics and are able to survive and multiply in the presence of an antibiotic. This issue has become one of the current threats to global health. Some bacteria that have developed resistance to antibiotics are MRSA (methicillin-resistant Staphylococcus aureus), VRE (vancomycin-resistant enterococcus), and ESBL (extended spectrum beta-lactamase) producing Enterobacteriaceae.

One of the key factors that aids resistance spreading between bacteria is transposons. Transposons have the ability to switch locations in the genome autonomously. When transferred between bacteria transposons can carry antibiotic resistance genes within them. Due to this threat, EMBL researchers are in the process of stopping this crisis. Throughout their study, the research team has proposed a molecular structure of transposons that can provide an explanation to the protein-DNA mechanism that inserts the transposons, including the resistance they carry, in recipient bacteria. This mechanism is possible because of the unusual shape of the transposase protein.  This lets it to bind to the DNA in an inactive state, which prevents cleavage and destruction of the transposon until it can paste the antibiotic resistance gene in the new host genome. The protein's special shape also forces the transposon DNA to unwind and open up allowing it to insert its antibiotic resistance lineage at many places in an extremely diverse range of bacteria.

Based on the proposed structure and understanding of the mechanism the EMBL researchers have developed molecules that would block the transposons movement. In theory, these molecules would be able to prevent the development of antibiotic-resistant bacteria. The EMBL researchers proposed two methods, one stops the transposase protein from going to its activated conformation by blocking its architecture with a newly designed peptide, a short chain of amino acids. The second method is a DNA-mimic that binds to the open site within the transposon, thus blocking the DNA strand replacement that is needed for resistance transfer. Of course, these two methods are only potential strategies. Therefore, there is still much more work to be done in the lab before these molecules are classified as being safe to the public.

First Home Testing Kit for Breast Cancer Mutations

The FDA has granted a genetic testing company the rights to distribute an at-home saliva test in order to determine one’s risk for three breast cancer gene mutations. 23andMe now offers these screenings as part of their Health and Ancestry product listed at $199. These saliva samples also provide individuals with ancestral history on their country of origin, as well as the genetic health risks that are involved in said areas. The test takes approximately two weeks to be analyzed and have a return of the results. Women are at an extremely higher risk of developing breast and ovarian cancer if they test positive for one of the BRCA1 and BRCA2 gene mutations. Men are also at a higher risk if they possess one of these genes, however it is much more uncommon for men to develop breast cancer (however not impossible). These mutations however, may lead to a higher risk of prostate cancer in men. Clients need to be aware; because if the at-home test states that you are negative for the gene mutations, it does NOT mean that you can’t get breast/ovarian cancer, since there are over 1,000 mutations associated with the BRCA gene. The Ashkenazi Jews (a derivative of Judaism of central Europe) are more likely to test positive for all three gene mutations than any other ethnical group. Donald St. Pierre of the FDA states that, “The test provides information to certain individuals who may be at increased breast, ovarian or prostate cancer risk and who might not otherwise get genetic screening, and is a step forward in the availability of direct-to-consumer genetic tests…this test should not be used as a substitute for seeing your doctor for cancer screenings or counseling on genetic and lifestyle factors that increase or decrease cancer risk”.

23andMe had originally reported these gene mutations back in 2010 without being approved by the FDA, however the FDA has issued them a warning in 2013. This caused the company to stop providing all health data until the FDA had reproducible results, and was proven statistically significant. A warning label is also not made mandatory on all test kits, stating that negative results do not rule out other genetic mutations associated with cancer risks, tests should not be used to determine medical treatment, tests should not be a substitute for a doctor’s visit, and that positive test results must be reviewed with their doctor in order to determine proper medical treatment. Ann Wojcicki the CEO of 23andMe, said that this product was made available due to high public demand.

This article was interesting to say the least.  It is nice for people with a background history of breast cancer to may find a a little piece of mind if they are positive or negative for these gene mutations, however I do not know about the quality of these tests.  $199 seems a little to good to be true to me, and since it is a newer product, I am not sure if I would trust the results or not.  I would personally stick to testing done through a licensed physician, or through a specialist with a more reputable product.

Bad Memory? Might be Due to Genetics

More than 100 genes have been identified to play a role in memory processing in the human brain. This study is a part of a relatively new field called “imaging genetics” it focuses on how genes determine structural and functional organization in the brain. Past studies that tried to link behavior and genes but lacked neural markers which can be essential to link to the two. The memory genes were able to be identified by using genotyping and brain imaging. The study used RNA in post- mortem brain tissue and intracranial EEG (iEEg) data from epilepsy patients alone with analyses from fMRI data linking resting- state brain behavior to specific genes. The RNA allowed researcher to determine gene expression. The iEEG data from epilepsy patients performing episodic memory task while electrodes would localize seizures essential inhibits function of specific parts of the brain. Interestingly some memory genes overlap with several genes associated with autism which bring about new research opportunities. I found this article to be interesting because it is combining genetics with cognitive neuroscience which I have not heard of before. Usually cognitive neuroscience is focused on what brain structure performs what function or what role does a certain neurotransmitter play. Now researchers are looking at the origin of these components which reflex upon the advancements of technology and understood knowledge. Also, I believe this study could continue and eventually help people who experience memory loss whether the loss is due to age, amnesia, or Alzheimer’s disease.

Sunday, March 18, 2018

Ant raids: It's all in the genes

Scientist has recently been studying certain ant attacks and have been intergrading their offspring into their own colonies in order for survival. They have recently discovered that these raids required to achieve the goals are controlled by a different gene in each of the closely related ant (Temnothroax). This proves that through the different changed in the genetic material is due to random. This means that although there are several different paths, they could all have the same outcome.

Within this research, the scientist at Johannes-Gutenberg University Mainz was able to identify two specific attack genes in slave maker ants. The first gene is “Acyl-CoA Delta (11) Desaturase which causes the attackers to release chemical scents during the raid. These scent mask the attackers, which helps them lead a successful raid. On the other hand the other gene that was identified was called Trypsin-7, which appears to have an affect on the recognition potential of identifying the host colonies required for a raid.

Stem Cell Therapy

 The Potential of stem cells in the treatment of traumatic brain injuries

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Traumatic brain injury (TBI) is a global public health concern, with limited treatment options available. In the U.S alone, between 3.2 -5.3 million people suffer long-term cognitive impairment as a result of TBI. When an individual has sustained a heavy blow to the head it could lead to long-term deficits involving sensory-motor and memory functions. However, the brain harbors neural stem cells that it uses to self-repair itself after damages have been sustained. Unfortunately, these neural stem cells are limited and if the impact to the head was strong it would result in a chronic injury. Therefore the brain would not be able to have a full recovery which would result in future health problems for an individual. As of today, many scientists have begun working with stem cells in hopes of finding a treatment for TBI.
Embryonic and Induced Pluripotent stem cells have acquired a lot of population due to there plasticity and ability to differentiate into any lineage in the nervous central system. Embryonic stem cells (ES) are obtained from fetal or embryonic brains and are strongly considered for neural transplantation because when implanted into a recipients brain these cells can differentiate, migrate, and make innervation to aid the damaged brain to recover. Induced pluripotent stem cells (iPSCs) are obtained from patients themselves and have the potential for autologous transplantation and avoiding ethical and graft rejection concerns. Induced pluripotent stem cells have allowed scientists to explore manipulating this highly plastic population. These somatic cell-derived iPSCs can provide large quantities of pluripotent cells that have high plasticity generating cells for all three germ layers including neurons and glial cells.
These unique properties of Embryonic and Induced pluripotent stem cells have raised hope that many neurological diseases including TBI might be cured or treated.

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Mystery Ailments and Mendelian Inheritance

Currently, scientists have discovered 7,000 Mendelian diseases and many have been discovered by screening adults and children. A recent study has shown that many Mendelian diseases and disorders go undetected. Using a electronic database and DNA samples, scientists found that 3.7 patients in the hospital system carried genetic variants linked to a disease. The researchers estimated that 4.5 percent of apparently non-genetic diseases are result of such mutations. A computer program was used to catch some of these hidden disorders by flagging down clusters of certain symptoms in patients. The use of this system could help doctors recognize disorders, and help patients better deal with their ailments. The co-author of this research, Dr. Joshua C. Denny, said that this study is just the tip of the genetic iceberg. Dr. Denny sees a need for much larger databases so more mutations can be discovered.
To expand their researcher, Dr. Denny and his colleagues turned to Vanderbilt University's hospital system. The researchers found 807 patients carrying mutations in genes for 17 diseases. Out of the 807 only 8 were actually diagnosed with a genetic disease. The mutations that were found often did not fit the standard profile for many diseases. Often the mutations patients had were recessive and they were carrying a single defective copy. Dr. Denny suspects that those carrying a single defective copy had a much milder versions of a disease than those with two copies. The researchers hope that more hospitals will look for Mendelian diseases in patients so as to provide better healthcare. I find this study very interesting because many of us could be walking around with a single copy of a defective gene and not even know it.

Astronauts Mark and Scott Kelly Are Still Identical Twins, Despite What You May Have Read

Scott Kelly spent a year in space on the International Space Station while his identical brother, Mark Kelly, stayed on Earth. There was a lot of media confusion and over exaggeration on what happened after Scott Kelly returned to Earth, as he was examined to see what has changed in his body compare to his brother. Many were stating that they were no long identical twins because Scott Kelly’s DNA changed, however, that is not the entire case, they are still as much of twins before Scott Kelly went to space. Scott Kelly’s DNA did not change, but there are observations in changes in his gene expression, which changed by 7% because of the stresses from the different environments he was in like, scuba diving, mountain climbing and being in space. Furthermore, as the article states, “Although 93% of genes’ expression returned to normal postflight, a subset of several hundred ‘space genes’ were still disrupted after return to Earth.” Researchers focus on studying the genetic effects of the twins for future missions, like going to Mars, and to understand the long term effects of space travels. There are also lots of physical effects on the body that are being studied after traveling in space like weakening muscles, risks of cancer from being exposed to radiation and the overall stresses on the body. With the results, scientists can research and find solutions to improve the human body's health and well being while being in space.

I thought this article was very insightful and interesting pertaining to genetics in space studies because there isn’t much research material available. NASA has a great opportunity to study this case of twins with one being in a controlled environment and the other exposed to another extreme environment. I was also interested in this article because I am currently reading Scott Kelly’s book called, “Endurance, A Year in Space, A Lifetime of Discovery” that goes through his life, including his brother Mark Kelly, and all the way up to his experience on the International Space Station.